This competing continuation application of the San Francisco AIDS Community Outreach Project will build on the previous ethnographic, street-based intervention model designed to prevent the spread of the human immunodeficiency virus (HIV) among intravenous drug users (IVDUs), their sexual partners, and prostitutes. At the core of the program is the deployment of Community Health Outreach Workers (CHOWs) who have been rigorously trained in ethnographic street techniques to engage target populations in natural settings and to educate them on effective methods to keep from contracting and spreading HIV. Included will be a special enhanced intervention which will build on IVDUs' dyadic relationships with "running buddies" and/or sexual partners and will focus on encouraging safer sex and needle hygiene and will lead to eventual drug abstinence. This intervention is in the form of a separate sample pre- test/post-test design. In addition, this project will participate in the national evaluation coordinated by NOVA Research as well as develop a through in-house process evaluation in order to improve interventions in an ongoing fashion.